Polyspecific binding molecules and uses thereof

Abstract

The present invention relates to polyspecific binding molecules and particularly single-chain polyspecific binding molecules that include at least one single-chain T-cell receptor (sc-TCR) covalently linked through a peptide linker sequence to at least one single-chain antibody (sc-Ab). Further disclosed are methods and compositions for testing and using the molecules.

Description

[0001] The present application claims priority to U.S. Provisional Application No. 60 / 105,164 filed on Oct. 21, 1998, the disclosure of which is hereby incorporated by reference.1. Field of the Invention[0002] The present invention relates to polyspecific binding molecules, as well as methods of making and using such molecules. In one aspect, the invention features single-chain polyspecific binding molecules that can damage or destroy target cells. The invention is useful for a variety of applications including use in associating cells that express a T-cell receptor or an antibody binding domain.2. BACKGROUND[0003] There has been recognition that immune system cells and particularly cytotoxic T lymphocytes (CTLs) can be used to detect tumor associated antigens (TAAs). For example, CTLs derived from melanomas have been used to identify a variety of melanoma-specific antigens. See e.g., Bruggen et al., Science, (1991), 254:1643; Bakker et al., J. Exp. Med., (1994), 179: 1005; and Yanu...

AI Technical Summary

Benefits of technology

[0043] The polyspecific binding molecules of the present invention provide several significant advantages.

[0052] The polynucleotides of the present advantage provide important advantages. For example, as will become apparent from the disclosure which follows, preferred polynucleotides of this invention include DNA segments that encode covalently linked scTCR and sc-Ab molecules. The DNA segments are preferably configured in a "cassette" format so that a segment encoding a sc-TCR or sc-Ab can be switched, as desired, with another segment encoding another scTCR or sc-Ab.

[0065] The recombinant bacteriophages of this invention have additional uses and advantages. For example, the bacteriophages can be used in accord with standard screening techniques to facilitate analysis of a desired polyspecific binding molecule in vitro. More particularly, the recombinant bacteriophages can be used to assess whether a specific sc-TCR or sc-Ab such as a sc-Fv has capacity to recognize, bind and / or kill target cells of interest. Additional advantages include a relatively fast and straightforward procedure for making and testing bispecific sc-TCR / sc-Ab molecules; a short and simple purification process; and an accelerated method for testing large numbers of different hybrid molecules for efficacy in damaging or killing target cells (e.g., tumor killing).

Problems solved by technology

However, this approach suffers from significant drawbacks.

For example, it is not always straightforward to isolate sufficient quantities of the CTLs from the patient.

In addition, at least some of the CTLs may have specificities that have survived self-tolerance that could lead to additional complications.

However, many of these attempts have been associated with problems.

In particular, it has been proposed that many bsFv molecules inadvertently interact with the shed antigens, thereby reducing tumor cell killing efficiency.

The prior immune molecules suffer from additional drawbacks.

Thus, in settings in which binding to specific cell surface peptides is needed, it has been difficult or impossible for bsFv molecules.

Further, it has been difficult to isolate some bsFv molecules without significant isolation and / or re-folding steps.

Preparation and use of many sc-TCRs has also been associated with problems.

For example, several prior methods for making the sc-TCRs have yielded insoluble and improperly folded molecules.

However, the sc-TCRs produced by these methods often require time-consuming manipulations to obtain even modest amounts of protein.

In contrast, most prior immune system molecules and particularly bsFv molecules are not optimized to bind pMHC or pHLA complexes.

In particular, there has been understanding that targetable antigens are often hidden inside cells making recognition and binding difficult.

In contrast, most prior recombinant immune system molecules are not able to bind MHC-or HLA-presented antigens effectively.

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